yield break example

// yield break example for Stack Overflow answer: http://stackoverflow.com/questions/3229698/how-can-i-return-an-empty-ienumerable/3229734#3229734

public IEnumerable<Friend> FindFriends()
{
  if(!userExists) yield break;

  foreach(var descendant in doc.Descendants("user").Select(user => new Friend
    {
        ID = user.Element("id").Value,
        Name = user.Element("name").Value,
        URL = user.Element("url").Value,
        Photo = user.Element("photo").Value
    }))
  {
    yield return descendant;
  }
}